Prior-art systems for salvaging blood from surgical sites and wound drains often employ disposable units that include a reservoir for collecting the blood-containing fluid and a separation device (such as a centrifuge bowl or disk) for separating out and washing the red blood cells (RBCs). The RBCs salvaged using these systems may be autotransfused back into the patient, thereby reducing the need for allogenic blood transfusions. Examples of such blood-salvage systems include those described in U.S. Pat. No. 6,251,291 to Lamphere et al., issued Jun. 26, 2001, and in U.S. Patent Application Publication No. 2005/0203469 by Bobroff et al., published Sep. 15, 2005. Both this patent and published application are incorporated herein by reference. Commercial examples of such systems include the OrthoPAT® Surgical Blood Salvage System and the CardioPAT™ Surgical Blood Salvage System, both of which are sold by Haemonetics Corporation of Braintree, Mass.
FIG. 1 shows a disposable set 20 that may be used in a prior-art cell-salvage systems used during surgery. The set 20 includes a centrifuge disk 35 connected to an inlet tube 18 and an outlet tube 38. The inlet tube 18 is connected to a reservoir 22 for collecting the blood and other fluids from a surgical site. The inlet tube 18 forms a permanent connection between the reservoir 22 and the centrifuge disk 35. This reservoir may be of the type described in U.S. Pat. No. 6,251,291, referred to above. The reservoir 22 includes port lines 11, through which the blood and other fluids are collected from the surgical site, and a vacuum inlet port 14, through which a partial vacuum is provided to the reservoir for drawing the blood and other fluids through the port lines. The inlet tube 18 is also connected to a saline air-elimination filter 53 and a saline spike 52, which may be connected to a source of saline, which may be used during the washing of the RBCs in the centrifuge disk 35. The outlet tube 38 is connected to an RBC bag 59 and a waste bag 58.
Blood and other fluids are suctioned from a surgical site and drawn into the reservoir 22. These fluids are drawn from the reservoir 22 into the centrifuge disk 35, which is then spun so as to separate out the RBCs from the plasma and other fluids. The plasma and other fluids may be directed to the waste bag 58. The RBCs may then be washed in the centrifuge disk 35 with saline from the saline source. After washing, the saline may be separated from the RBCs and directed to the waste bag 58, and the washed RBCs directed to the RBC bag 59. The RBCs may then be retransfused to into the patient.
Often the amount of blood collected in the reservoir is insufficient to carry out the separation and wash procedures. In such a situation, because the reservoir and separation chamber are permanently connected by tube 18, the entire disposable set 20 must be discarded after the procedure, even though the centrifuge disk 35, the RBC bag 59 and waste bag 58 are not utilized. Discarding the entire disposable even though the separation chamber is unused is wasteful and adds unnecessary expense to surgical procedures that ultimately do not lead to washing and reinfusing of blood to the patient.